Résumé : On the basis of interviews, we highlight important historical elements with potential traumatic implications in order to understand some of the psychological roots of the current conflict-ridden relationship between French-speaking and Flemish Belgian citizens. We suggest that this conflict has a complex psychodynamic structure. Due to former experiences of shame, humiliation, disdain and contempt, two concomitant but asymmetrical defensive processes can be observed: repression in the French-language group, dissociation or rejection in the Flemish group. In particular, we hypothesize that the war experiences traumatized the Flemish identity in a complex way, generating an internal defensive pressure characterized by dissociation. The impact of these psychological processes on the current political situation is explored.